A conventional tip dresser includes a plate-shaped cutter, a holder to which the cutter is attached, and a rotary drive portion that holds rotatably the holder to which the cutter is attached (for example, refer to Patent Document 1). To enable simultaneous cutting of tip end faces of the tip end portions of a pair of electrode tips opposed to each other and expanding portions expanding from the tip end faces, this cutter has cutting blades having substantially ¼ arc shapes corresponding to the external shapes of substantially the halves of the tip end portions on one side with respect to the central axis of the pair of electrode tips so that the cutting blades are provided on both edges in the width direction of the tip end sides disposed on the central axis side of the electrode tips at the edge of the surface side being one side in the thickness direction. The cutter has an attaching hole perforating through the cutter on a base portion side away from the portion between the two cutting blades.
The holder has receiving surfaces recessed so as to receive tip end portions of a pair of electrode tips on both end face sides, and an attaching surface which is a part of a discharging recess for discharging shavings formed to penetrate along a rotation central axis at the time of cutting that matches the central axis of the electrode tips, and to the attaching surface, the cutter is attached by putting the back side that is opposite to the surface side of the cutter and becomes the cutting blade side on the attaching surface and screwing an attaching screw inserted through the attaching hole.
When a breaker for discharging shavings is disposed, the breaker is disposed on the surface side of the cutter, and is constituted by the head portion of the attaching screw or a welded triangular plate (for example, refer to Patent Document 2).